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P. S. Hampson

Publications and source records attributed to P. S. Hampson.

6 recordsLinked to original sources
USGS1993

Hydrology and water quality of Reedy Creek in the Reedy Creek Improvement District, central Florida, 1986-89

The Reedy Creek Improvement District encompasses an area of about 43 sq mi in southwestern Orange and northwestern Osceola Counties in central Florida. The District operates a wastewater-treatment plant that discharges through two forested wetland areas and a percolation-pond system into Reedy Creek. Discharges from these wetland systems provide a relatively steady base flow which maintains streamflow in Reedy Creek during periods of low rainfall. Streamflows during the study were characterized by relatively long periods of below-average discharge interspersed with periods of high discharges. The highest mean discharges were recorded in 1988 and the lowest mean discharges were recorded in 1989. Water-quality data collection included the operation of four continuous water-quality monitors recording hourly water temperature, specific conductance, and dissolved oxygen concentration, and the collection of water-quality samples. Dissolved oxygen concentrations were similar for all stations on Reedy Creek and frequently were less than the minimum Florida standard of 5.0 mg/L. These low dissolved oxygen concentrations probably are the result of natural conditions. Nutrient analyses of water-quality samples were used to compute loadings into and out of a wetland conservation area in the southern part of the District and in the reach of Reedy Creek downstream from the wastewater discharges. Overall retention percentages for 1986-89, not including atmospheric and precipitation inputs, were 59.1 percent for total ammonia nitrogen: 3.4 percent for total organic nitrogen, which was the predominant nitrogen species: 33.2 percent for total nitrate nitrogen; 27.0 percent for total phosphorus; and 26.0 percent for total organic carbon. Highest loading inputs to the wetland conservation area were from the reach of Reedy Creek receiving wastewater discharge. Discharges from the wetlands receiving wastewater and entering the wetland conservation area during 1988 carried 16.3 percent of the total nitrogen load, and 25.0 percent of the total phosphorus load: during 1989 the discharges carried 22.0 percent of the total N and 21.0 percent of the total P.

Water-Resources Investigations Report↗
USGS1989

Measurement of reaeration coefficients for selected Florida streams

A total of 29 separate reaeration coefficient determinations were performed on 27 subreaches of 12 selected Florida streams between October 1981 and May 1985. Measurements performed prior to June 1984 were made using the peak and area methods with ethylene and propane as the tracer gases. Later measurements utilized the steady-state method with propane as the only tracer gas. The reaeration coefficients ranged from 1.07 to 45.9 days with a mean estimated probable error of +/16.7%. Ten predictive equations (compiled from the literature) were also evaluated using the measured coefficients. The most representative equation was one of the energy dissipation type with a standard error of 60.3%. Seven of the 10 predictive additional equations were modified using the measured coefficients and nonlinear regression techniques. The most accurate of the developed equations was also of the energy dissipation form and had a standard error of 54.9%. For 5 of the 13 subreaches in which both ethylene and propane were used, the ethylene data resulted in substantially larger reaeration coefficient values which were rejected. In these reaches, ethylene concentrations were probably significantly affected by one or more electrophilic addition reactions known to occur in aqueous media. (Author 's abstract)

Water-Resources Investigations Report↗
USGS1986

Effects of detention on water quality of two stormwater detention ponds receiving highway surface runoff in Jacksonville, Florida

Water and sediment samples were analyzed for major chemical constituents, nutrients, and heavy metals following ten storm events at two stormwater detention ponds that receive highway surface runoff in the Jacksonville, Florida, metropolitan area. The purpose of the sampling program was to detect changes in constituent concentration with time of detention within the pond system. Statistical inference of a relation with total rainfall was found in the initial concentrations of 11 constituents and with antecedent dry period for the initial concentrations of 3 constituents. Based on graphical examination and factor analysis , constituent behavior with time could be grouped into five relatively independent processes for one of the ponds. The processes were (1) interaction with shallow groundwater systems, (2) solubilization of bottom materials, (3) nutrient uptake, (4) seasonal changes in precipitation, and (5) sedimentation. Most of the observed water-quality changes in the ponds were virtually complete within 3 days following the storm event. (Author's abstract)

Florida↗
USGS1984

Effects of hydraulic borehole mining on ground water at a test site in northeast St Johns County, Florida

An experimental mining project was conducted in northeast St. Johns County, Florida, to determine the feasibility of extracting deeply buried phosphate ore by hydraulic borehole mining techniques. The phosphate zone is between 232 and 250 feet below land surface and consists of approximately equal proportions of fine-grained phosphate, sand, and clay. Six wells were constructed at the test site to monitor effects of the mining operation on the ground-water resources of the area. One well penetrated the Floridan aquifer beneath the phosphate zone, another was completed in the phosphate zone, and the other four were finished in water-bearing zones above the phosphate zone. The mining project consisted of three separate tests in which different mining methods were used. Changes in water levels, other than in the mined zone, were detected only in the overlying monitored zone during the first two tests as a result of roof failures in cavities formed by the mining operation. Water-quality changes were observed only in the mined zone and resulted from the injection of water from the deeper Floridan aquifer as part of the mining operation. (USGS)

Water-Resources Investigations Report↗
USGS1984

Ground-water resources of St. Johns County, Florida

The primary sources of water in St. Johns County are the surficial and Floridan aquifers. The surficial aquifer is the principal source of public and rural water supplies in most of the county. The Floridan aquifer serves as the major source of water for irrigation. In much of the county, water from the Floridan aquifer does not meet secondary drinking water standards established by the U.S. Environmental Protection Agency. The surficial aquifer is comprised of deposits of clay, sand, shell, and coquina that extended to a maximum depth of about 120 feet below land surface. Yields to 2-inch wells tapping the aquifer range from 1 to 40 gallons per minute and water generally meets drinking water standards. The Floridan aquifer consists of limestone and dolomite of Eocene age. In St. Johns County, the top of the aquifer ranges from about 89 to more than 360 feet below sea level. Yields from 4-inch wells range from 100 to several thousand gallons per minute. The presence of ancient seawater and the dissolution of gypsum and anhydrite are the primary factors governing water quality in the aquifer. In the southwest part of the county, intensive pumpage for irrigation has resulted in substantial increases in chloride concentration.

Florida↗